The present invention relates to dumbbells and relates more particularly to a built-up dumbbell which can be conveniently alternatively set into a any of a variety of forms to suit individual physical strength.
Dumbbell is a device very convenient and practical for muscular exercise. Because it does not occupy much space and is inexpensive, it is widely accepted by the people of all ages who like to exercise the muscles. According to conventional structure, a dumbbell is generally made of iron in a solid unit through casting process, having two unitary, round weights joined by a short bar. Because it is made in a solid unit, it makes transportation and packing difficult. It is too simple in structure to sell at a profit-yield price and therefore, few distributors would like to promote the selling. Further, it can not be adjusted in weight to meet individual requirement or physical condition.
To eliminate the aforesaid problems, there is disclosed an adjustable dumbbell. This structure of adjustable dumbbell, as shown in FIG. 6, is generally comprised of a handlebar and a plurality of pairs of weights which are made according to the same specification. The weights are attached to the handlebar through screw joint by O-rings, rubber caps and lock nuts. This structure of adjustable dumbbell is still not satisfactory in use because of the following disadavantages.
1. It is difficult to mount or dismount the weights; PA0 2. The fastening accessories may be damaged easily to affect the performance of the dumbbell; and PA0 3. Because the weights are made according to the same specification, it can not be arranged into a variety of forms to meet every individual's physical strength.